Stents are tubular structures that are implanted inside the lumen of a vessel or other body passageway to retain the patency of the vessel or passageway. Typically, stents are inserted into the lumen in a contracted condition and then either are expanded in situ with the aid of a catheter balloon, or expand autonomously. If an angioplasty procedure were performed without stent implantation, restenosis may occur as a result of elastic recoil of the stenotic lesion.
Various stent designs are known in the art and typically comprise a tubular body that expands from a contracted condition to a deployed condition. A common drawback of such stents is that the stent decreases in length, or foreshortens, along its longitudinal axis as it expands. Such foreshortening is undesirable because, in the deployed configuration, the stent may not span the entire area inside a vessel or orifice that requires expansion and/or support. In addition, foreshortening may result in non-uniformity of the stent in the deployed configuration.
Therefore, it would be desirable to provide a stent that has a radial stiffness in the expanded deployed configuration sufficient to maintain vessel patency in a stenosed vessel.
Further, it would be desirable to provide a stent that experiences reduced foreshortening, thereby reducing stent non-uniformity resulting from contraction and subsequent expansion.
Still further, it would be desirable to provide a stent that retains a homogenous cross-section and stress distribution after deployment.